1. Field of the Invention
The present invention relates to a cooling structure in an image forming apparatus.
2. Description of the Related Art
In an image forming apparatus, an image forming section requires a cooling process because heat is generated by operation of the image forming section which has electronic components including a power supply section to supply the apparatus with electric power, and a toner cartridge, a process unit, a laser unit, and the like to form an image on a sheet.
If there are plural heat generating portions (to be cooled), cooling fans may be provided so as to correspond respectively to these portions, thereby cooling these portions. In this structure, however, the number of cooling fans to be placed increases, undesirably from the viewpoint of space-saving and cost-reduction.
In recent years, a disclosure has hence been made of a technique of introducing a cooling wind blowing from one cooling fan to plural cooling targets to be cooled, thereby to cool efficiently the inside of the apparatus with an extremely reduced number of cooling fans placed (Jpn. Pat. Appln. Laid-Open Publications No. 2003-316237 and No. 2003-140534).
However, a kind of unit like a process unit which generates a predetermined air-pollutive gas such as ozone and another kind of unit like an electronic component which does not generate any gas are included, mixed in cooling targets in the image forming apparatus as described above. Therefore, even with the structure which simply introduces a cooling wind from one cooling fan to plural cooling targets like in the conventional technique as described above, a part of the cooling wind which includes ozone (or a predetermined gas) mixed by cooling the process unit may be mixed in other parts of the cooling wind which are guided to other portions which do not generate any gas, such as the electronic component and the laser unit. If a part of cooling wind polluted by a predetermined gas is mixed with other parts of cooling wind which have not been polluted, the predetermined gas mixed in these other parts of cooling wind may be discharged to the outside of the apparatus without being treated by a filter or the like provided for the predetermined gas.